User manual

Chapter Three Operation
Man_805U Rev 1.9 Page 23
Successful Communications
Source Module
Destination Module
• Serial data is received
• Serial RX LED flashes
•
Listen to ensure channel is
clear
• If clear, transmit message
• Radio TX LED flashes
-------------->
• Receive message
• Radio RX LED flashes
•
Check system and destination
address
• If OK, check error-check
•
•
• Radio RX LED flashes
<--------------
• If message okay, transmit back
an ACK message.
• Radio TX LED flashes
•
Acknowledgment received
okay - communication
complete
• Serial data is output
• Serial TX LED flashes
Unsuccessful Communications
Source Module
Destination Module
•
Listen to ensure channel is
clear
• If clear, transmit message
• TX LED flashes
------------->
• Receives message
• RX LED flashes
•
Check system and destination
address
• If incorrect, transmit no message
and no serial output.
• No ACK received
• Retry up to four times
------------->
• If no ACK message received
after five attempts
•
“NO CARRIER” message
sent to host
• DCD signal and DCD LED
reset